At London Metal Exchange, Mystery Buyer Holds 50-80 % of Copper

A mystery buyer is apparently holding more than half of the copper stocks at the London Metal Exchange's warehouses, the latest revelation of how a single trader can roil an entire commodities market.

That trader, whom the exchange hasn't identified, owns between 50% and 80% of the 355,750 metric tons held in LME-listed warehouses. This amounts to more than 177,875 metric tons of copper, valued at about $1.5 billion. The exchange first disclosed the large position on Nov. 23 in its daily inventory holder report.